Does a ResultSet load all data into memory or only when requested?

Question

I have a .jsp page where I have a GUI table that displays records from an Oracle database. This table allows typical pagination behaviour, such as \"FIRST\", \"NEXT\", \"PRE

Answer 1

lets say we have a table that contains 500 records in it

PreparedStatement stm=con.prepareStatement("select * from table");
stm.setFetchSize(100);// now each 100 records are loaded together from the database into the memory,
// and since we have 500 5 server round trips will occur.
ResultSet rs = stm.executeQuery();
rs.setFetchSize (50);//overrides the fetch size provided in the statements,
//and the next trip to the database will fetch the records based on the new fetch size